Question

The south west monsoon is characterised by wet and dry spells. What is the reason for this pulsating nature of the monsoon?

Answer 1

There are many predictions that global warming should cause heavier downpours and more frequent dry spells. That's what we've found here, but India is a complex region, so we want to be sure before we point the finger at global warming or any other cause," says Noah Diffenbaugh. 

Answer 2

this is because in the winter the monsoon winds come from. the side of Arabian penesula and from there in the red Sea and other water bodies it contains moisture and because of that the South west monsoon are characterized by wet dry spells.